It's one of the worst-kept secrets of family life that all parents have a preferred son or daughter and the rules for acknowledging it are the same everywhere: The favored kids recognize their status and keep quiet about it - the better to preserve the good thing they've got going and to keep their siblings off their back.
A system of education which would not gratify this disposition in any party is requisite in order to obviate the difficulty and the reader will find a something said to that purpose in perusing this tract.